(a) Field of the Invention
The present invention is related to a series and parallel combined dual power drive system for the engine functioning as the active rotation power source to directly drive a load, the system provides the following functions:                Operating as a series combined power system, wherein, the engine drives a primary dynamo-electric unit to function as a generator with the power generated to drive a secondary dynamo-electric unit to output mechanical rotation kinetics to drive the load and regulate the engine to operate at a constant speed yielding higher energy efficiency; the constant speed operation is defined as the range of operation speed wherein the engine is running at lower fuel consumption but paid the operation region with comparatively higher fuel saving of comparatively higher output power so to reach the brake specific fuel consumption; or when an optional rechargeable device is added to the system, the power generated by the primary dynamo-electric unit as driven by the engine charges the rechargeable device, or the power from the rechargeable device and that from the primary dynamo-electric unit jointly drive the secondary dynamo-electric unit to function as a motor to output to regulate the engine operating in a constant speed of comparatively higher energy efficiency; again, the constant speed operation is defined as the range of operation speed wherein the engine is running at lower fuel consumption but paid the operation region with comparatively higher fuel saving of comparatively higher output power so to reach the brake specific fuel consumption;        The load is driven by the rotation kinetics from the engine power;        When adapted with the optional rechargeable device, the system provides the operation of the parallel combined power system for the power from the rechargeable device to drive either or both of the primary and the secondary dynamo-electric units to function as a motor to jointly drive the load with the power from the engine, or in case of a light load, the kinetics form the engine is used to drive either or both of the primary and the secondary dynamo-electric units to function as a generator to charge the rechargeable device or supply power to another load;        The power from the rechargeable device drives either or both of the primary and the secondary dynamo-electric units to function as a motor for driving a load;        The power from the engine drives either or both of the primary and the secondary dynamo-electric units to function as a generator to charge the rechargeable device or to supply power to another load;        The load is used to inversely drive either or both of the primary and the secondary dynamo-electric units to function as a generator to charge the rechargeable device or supply power to another load;        Mechanical damper of the engine functions as the brake, or if the rechargeable device is adapted, either or both of the primary and the secondary dynamo-electric units operates at the same time as a generator to charge the rechargeable device or to supply power to another load for creating the braking function by regeneration;        The rechargeable device drives either or both of the primary and the secondary dynamo-electric units to function as a motor to start the engine; and        The system provides all or any part of those functions described above.The system by providing all or any part of those functions described above corrects the defectives of the lower efficiency and higher pollution found with the engine when operating at low power output and low speed.        
(b) Description of the Prior Art
Conventional land, surface or air carriers are usually provided with a single power system. In recent years, as demanded by energy saving and pollution control appeals, major efforts have been put into the research and development of dual power drive system. Wherein, significant progress has been down in the combined dual power system containing rotation kinetics outputted form a combustion engine and that outputted from a power driven motor. Looking back those combined dual power systems already having been developed, they include:    1. Series combined power system: the engine is used to drive the motor, in turn, the power from the generator drives the motor to create rotation kinetics to drive the load; this system has its flaw in a wild difference in the efficiency of the system under various load rate; large dynamo-electric rated capacity, consuming too much space, heavier and higher cost since the motor and the generator bear all the powers;    2. Energy storage series drive system: with normal load, the engine is used to drive the generator, in turn, the power from the generator drives the motor to output rotation kinetics to drive the load; in case of a light load, the power from generator while driving the motor, is partially inputted into the rechargeable device for storing energy so that if the engine stops running, the power from the rechargeable device drives the motor to output rotation kinetics to drive the load for reducing pollution and upgrading energy efficiency; in case of a heavy load, the power from the generator as driven the engine and that from the rechargeable device are jointly outputted to the motor to output rotation kinetics for driving the load;    3. Parallel combined power system: with a normal load, the rotation kinetics outputted from the engine directly drive the load; in case of a light load, the motor drawn by the engine is switched to function as a generator to charge the rechargeable device or to supply power to another load; or if the engine stops running, the power from the rechargeable device drives the motor to output rotation kinetics for driving the load to upgrade energy efficiency and reduce pollution; and in case of a heavy load, the rotation kinetics outputted from the engine and that from the motor as driven by the rechargeable device jointly drive the load; the flaw of the system rests in that it requires the rechargeable device with sufficient capacity.